A potentiometer includes a resistive element, usually arranged in a semicircular configuration. A sliding contact is movable along the resistive element, as by rotating a shaft containing the contact. The resistive element and slider are electrically connected so that the device functions as an adjustable voltage divider or rheostat.
Potentiometers may be used for the control of a wide variety of electronic and electric equipment. Rotation of the potentionmeter shaft alters the resistance of the potentiometer and effects the desired control in the apparatus.
In many instances, it is necessary or desirable to prevent inadvertant movement of potentiometer knob from operating the potentiometer and altering the condition of the equipment controlled thereby. It is further often necessary or desirable to limit the amount by which the potentiometer shaft may be rotated so as to limit certain operative conditions in the equipment.